This project is concerned with the identification and characterization of components of the lung associated with pulmonary diseases which could provide information concerning the disease processes as well as function as diagnostic markers of pulmonary damage or disease. Current attention is being focused on (1) the enzyme components of human amniotic fluid which originates in the fetal lung; (2) the particulate materials, and soluble proteins present in the lungs of patients with alveolar proteinosis. The objectives are as follows: (1) to identify lung-specific enzymes and proteins which are released into serum or the pulmonary airways following the production of cellular damage by inhaled toxicants, (2) to investigate and characterize unusual enzymes, proteins, cells and particulate materials present in diseased lungs, and (3) to identify enzymes or proteins in human amniotic fluid which originate from the fetal lung and to investigate the use of such components to predict fetal lung maturity.